|Exterior Scene Part 3 – Lighting |
Author: Neoscape:Hao La
Lighting is one of the most important parts in 3D visualization rendering. It brings not only the look and feel for the image, but also helps to visualize the design in reality. Many artists will find themselves spending more time with interior lighting to make sure every detail in the room is lit perfectly. Exterior lighting is easier to set up but still challenges the artist.
Here we have a model of L5’s exterior. The entire model is created based on a CAD plan, then imported into 3D Studio Max and organized into layers.
Textures and material information are collected and then applied to the model.
All the materials in the scene are Vray materials.
In this scene, besides some basic material, we also apply Vray displacement on the grass to make the render look more realistic and detailed.
For the grass, we use 2D mapping type for Vray DisplacementMod with a grayscale grass bitmap for displacement effects.
3. Camera View Setup
After applying all textures to the model, we set up a couple views and end up with this final view.
Similar to lighting an interior scene, we start with environment light first. Again, it is a good practice to collect all the reference images about the kind of lighting you want to apply into the scene. In this case, we want to use daylight with yellow sunlight coming down from the right and hitting the whole building’s section. The right part of the scene will be in bluish shadow. Both yellow and blue colors will compliment the image.
Instead of using GI Environment (skylight) in Vray render setting dialogue as we used in interior to create ambient light, we use a different way by creating a semi-dome to simulate the sky.
We apply VrayLightMtl with a Sky bitmap for the dome, and also apply UVW mapping cylindrical type for it as well. The benefit of this method is that it creates more natural-looking ambient light and it has bright and dark areas just like a real sky would look. When applying the bitmap on a VraylightMtl, it will reflect those dark and bright areas on the bitmap onto the object to create a more interesting look for the image.
This method sounds the same as the HDRI method but easier to create and adjust since you can move, rotate or even scale the map on the viewport to suit your lighting look or even reflection on the object. Unlike HDRI, you have to enable the background on your viewport and put in some numbers to get it to look right.
For now, we leave the value of brightness at 1.
After that, we can go ahead and do a test render. We used a very low setting for test rendering images in order to get a quick preview of the image.
>Color mapping: Exponential
>Irradiance map was set to low
>Light cache with Subdivs at 200 and sample size at 0.02
It looks very dark at this point, but we can see some interesting effects on the ambient light. Since we are aiming for a bright-looking day, we need to increase the multiply of the VraylightMtl from 1 to 6.
Do the test again to see how it looks.
This looks better. We get the shadow to look bluish as we wanted. The render’s quality looks really bad due to very low setting of GI, however we will set a higher setting after we get the lighting to look right. This way can save you a lot of time.
Now, after you get the correct look for the ambient, let’s add some sunlight. Again, we use Vray light, Sphere type to simulate the sun, with strong yellow color. The bigger the radius of the light, softer the shadow.
We also add furniture, some plants, flowers and trees to add more details into the scene.
Now, we are ready for the final render.
5. Render Setting For Final Image
For a final render image at 4000 pixel, we change the setting so that it is higher than before to bring more quality to the image.
For GI method, we used Irradiance map for Primary bounces and Light cache for Secondary bounces at a high setting.
We chose Adaptive QMC for Image sampler and Michell – Netravali for Antialiasing filter.
For post work, we also rendered out the VrayReflection pass, VraySpecular pass and VrayZDepth pass (you can add these passes by going to Render Elements and click the Add button).
6. Post Work
We use Photoshop for post work. Level adjustments and Color Balance are used to improve the contrast and color for the image.
A real sky background is added for more realism.
Reflection and Specular passes are used to add more reflection and highlight for the image to provide more realistic effects.
We also render out a Vray Dirtpass render so we can use it in Photoshop to boost the shadow.
Some close-up details:
And there it is. We get the lighting as we wanted. It is quite simple as you can see, but it sure is full of challenges to get the right look for the final image. I hope you will get other ideas in lighting an exterior scene as well.
All Links for Exterior Scene Tutorials:
1. Exterior Scene Part 1 >>
2. Exterior Scene Part 2 >>
3. Exterior Scene Part 3 >>
4. Exterior Scene Part 4 >>